This application relates to enhancing structure diagram generation.
A molecule is typically represented in a computer by a connection table that identifies atoms in the molecule and specifies connections (“bonds”) among the identified atoms. The connection table may also describe associated properties such as atom type, bond order, charge, and stereochemistry. A diagrammatic representation of the molecule may be derived from the connection table. Examples of a connection table and a corresponding diagram are illustrated in FIGS. 1A–1B (for clarity, hydrogen atoms are not shown).
In chemistry, with reference to FIG. 2, a chain of atoms that closes on itself is known as a ring. In the context of a ring or a ring system (see below), a bridge is a chain of atoms that begins at an origin point (which is an atom) in the ring or system, and connects back to the same ring or system at least two atoms away from the origin point, to form an additional ring. A chain that reconnects at the same origin point instead is known as “spiro”. A chain that reconnects to an atom that is adjacent to the origin point is known as “fused”.
A ring system, which is also known as a “cyclic system”, is a group of rings such that (1) each ring shares one or more bonds with another ring in the group and (2) the group cannot be divided into smaller cyclic systems. An arrangement in which two rings are connected by a linking, non-cyclic (“acyclic”) bond is considered to include two cyclic systems, not one. As used herein, “ring system” has a meaning consistent with an understanding that a spiro ring includes two distinct ring systems.